Breastpumps for the purpose of extracting breastmilk from a nursing mother are well-known and generally comprise: a breastshield (also known as a shield) that is typically funnel-shaped and fits over the breast; a vacuum source connected to the breastshield for generating an intermittent vacuum within the breastshield such that milk is expressed from the breast; and a conduit structure for communicating milk from the breastshield to a receptacle for the expressed milk, as well as for communicating pressure variations (such as the foregoing vacuum) to the breastshield. While breastpumps that can be attached to motorized vacuum sources are available, there are occasions when mothers cannot conveniently plug a breastpump into an external vacuum source or an electrical outlet is not available. Battery-powered breastpumps are a good alternative. However a mother who wishes to draw milk from her breast (that is “express” milk) must, or otherwise may choose to, rely on a manual pump as the vacuum source.
Many manual pumps must be operated by two hands, one to hold the assembly in place and the other to drive the pump. One can refer, for example, to U.S. Pat. Nos. 4,857,051 and 6,110,140. Alternatively, manual pumps that do provide for one-handed use are often difficult to operate.
Moreover, existing manual breastpumps are not made to differentiate between different phases of the milk expression process, or equipped with a mechanism or method of operation to accommodate the different phases. That process includes, for example, a period before breastfeeding, referred to as the milk ejection period, or “letdown”, in which effective removal of the milk from the breast is initiated by the suckling action of a baby's mouth and jaw to produce or stimulate an ejection reflex, in which stored milk is released and made available for expression.
The milk ejection reflex is the neurohormonal reflex resulting from the tactile stimulation of the nipple sending neuronal impulses to the hypothalamus, and the neurohypophysial release of oxytocin into the systemic circulation. The subsequent contraction of the myoepithelial cells within the breast caused by oxytocin moves milk from the alveoli into the collecting ducts and forward to the nipple. Milk ejection, or the milk ejection period, is the interval when an increased availability of milk from the nipple is caused as a result of the stimulation of the milk ejection reflex. Milk ejection in women normally lasts for approximately two minutes. The ejection reflex will be identified in the following also as “ejection”.
The level of pressure applied and the intermittency of the stimulation for initiating ejection are different than the level and intermittency of the action for actually expressing the breast milk. Conventional manual breastpumps do not provide a method or mechanism by which a user can easily stimulate an ejection reflex and subsequently commence to efficiently express breastmilk.
A demand therefore is present for a breastpump that is used to easily produce stimulation to initiate ejection and in addition there is also demand for an improved breastpump that provides efficient expression of breastmilk by manual operation thereof. The present invention satisfies these demands, and others.